Savio 20/1 MFS User Manual page 49

Fault finding
ref. 23 Supply voltage should be indicated when the
appliance is started with an open thermostat or timer.
Set the tester to VAC.
ref. 24 The correct position of the lever on the 3---way valve
during normal operation is shown in the picture (the
lever should be positioned toward the right, as seen
from the front of the appliance).
ref. 25 If power is not being supplied to the 3---way valve, the
lever must move freely over the first half of its travel
from left to right. Also, the lever must meet resistance
when moved over the remaining half of its travel from
left to right. If the lever moves freely from left to right
over its entire travel, the 3---way valve is jammed or
faulty. Substitute the valve.
ref. 26 When the contacts open in the main circuit flow switch,
the voltage across the points shown in the diagram
should increase from 0 volts to supply voltage. Set the
tester to VAC.
ref. 27 Power is being supplied to the 3---way valve when sup-
ply voltage is measured across the points shown in the
diagram. Set the tester to VAC.
ref. 28 If 12 VDC is measured across the points shown in the
diagram, the contacts are open in the d.h.w. flow
switch. If 0 volts are measured, the contacts are
closed. Set the tester to VDC.
ref. 29 Disconnect the flow switch on the d.h.w. circuit and
connect an ohmmeter as shown above. The contact in
the sensor on the flow switch is normally open (resis-
tance at infinity). Withdrawing a sufficient quantity of
d.h.w. the contact must close (resistance zero). Set the
tester to ohm.
ref. 30 At the electronic regulation p.c.b, disconnect the cable
from the 3---way valve to the board. Measure the resis-
tance across the cable, which should be 1700 ohm.
Set the tester to ohm.
rev. 17.09.93
47